Concordance of three alternative gestational age assessments for pregnant women from four African countries: A secondary analysis of the MIPPAD trial

PLoS One. 2018 Aug 6;13(8):e0199243. doi: 10.1371/journal.pone.0199243. eCollection 2018.

Abstract

Background: At times, ultrasound is not readily available in low resource countries in Africa for accurate determination of gestational age, so using alternative methods is pivotal during pregnancy. These assessments are used to aid the risk analysis for an infant and management strategies for premature delivery, if necessary. Currently, date of last menstrual period, fundal height measurements, and the New Ballard Score are commonly used in resource-limited settings. However, concordance of these measures is unknown for sub-Saharan Africa. We obtained data from an open-label randomized controlled trial, to assess the concordance of these alternative assessment methods. The purpose of our study was to determine the agreement between these alternative methods when used in sub-Saharan African populations.

Methods: A total of 4,390 pregnant women from Benin, Gabon, Mozambique and Tanzania were included in our analysis. The assessment methods compared were: 1) reported last menstrual period, 2) symphysis-fundal height measurement, and 3) the New Ballard Score. The Bland-Altman method and intraclass correlation coefficient (ICC) were used to test the degree of agreement. Survival range gestational age, used as an inclusion criterion for further analysis, was from 22 to 44 weeks.

Findings: Plots showed a lack of agreement between methods and the 95% limits of agreement too wide to be clinically useful. ICC = 0.25 indicated poor agreement. A post-hoc analysis, restricted from 32 to 42 weeks, was done to check for better agreement in this near-term population. The plots and ICC = 0.16 still confirmed poor agreement.

Conclusion: The alternative assessments do not result in comparable outcomes and discrepancies are far beyond the clinically acceptable range. Last menstrual period should not be used as the only estimator of gestational age. In the absence of reliable early ultrasound, symphysis-fundal height measurements may be most useful during pregnancy for fetal risk assessment and the New Ballard Score after delivery as a confirmation of these estimations and for further neonatal management. However, promotion of portable ultrasound devices is required for accurate assessment of gestational age in sub-Sahara Africa.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Benin / epidemiology
  • Female
  • Fetal Development / physiology
  • Gabon / epidemiology
  • Gestational Age*
  • Humans
  • Infant, Newborn
  • Middle Aged
  • Mozambique / epidemiology
  • Pregnancy
  • Reproducibility of Results
  • Retrospective Studies
  • Tanzania / epidemiology
  • Ultrasonography, Prenatal* / statistics & numerical data
  • Young Adult

Grant support

The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. This study was funded by the European Developing Countries Clinical Trials Partnership (EDCTP; IP.2007.31080.002) (CM), the Malaria in Pregnancy Consortium and the following national agencies: Instituto de Salud Carlos III (PI08/0564), Spain; Federal Ministry of Education and Research (BMBF FKZ: da01KA0803), Germany; Institut de Recherche pour le Développement (IRD), France. CANTAM provided infrastructure help in the study. RG was partially supported by a grant from the Spanish Ministry of Health (ref. CM07/0015). The CISM receives core funding from the Spanish Agency for International Cooperation (AECI). LLITNs (Permanet) were donated by Vestergaard Fransen. Austrian Ministry of Science, Research and Economy and Deutsches Zentrum für Luft- und Raumfahrt (MR) and the Bill and Melinda Gates Foundation (CM). There was no additional external funding received for this study.